Palast's investigation into the Bush family fortunes for his column in The Observer led him to uncover a connection to a company called ChoicePoint. In an October 2008 interview Palast said that before the 2000 Election ChoicePoint "was purging the voter rolls of Florida under a contract with a lady named Katherine Harris, the Secretary of State. They won a contract, a bid contract with the state, with the highest bid."[9]

After subsequently noticing a large proportion of African-American voters were claiming their names had disappeared from voter rolls in Florida in the 2000 election, Palast launched a full-scale investigation into voter fraud, the results of which were broadcast in the UK by the BBC on their Newsnight[10] show prior to the 2004 Election. Palast claimed to have obtained computer discs from Katherine Harris' office, which contained caging lists of "voters matched by race and tagged as felons."[9]

After Palast was invited by Robert F. Kennedy, Jr. to appear on his Air America talk show to discuss, among other things, election fraud, the pair teamed up to find out if democracy was in a better state in 2008. In their report, which was published in October 2008 in Rolling Stone, they concluded that the 2008 election had already been stolen. "If Democrats are to win the 2008 election, they must not simply beat John McCain at the polls -- they must beat him by a margin that exceeds the level of GOP vote tampering", Palast and Kennedy summarized.[13]

To combat the extensive acts of voter suppression that Palast and Kennedy uncovered, the duo launched a campaign called Steal Back Your Vote,[14] which features a website and free downloadable voter guide / adult comic book.

Palast has also taken issue with the official story behind the grounding of the Exxon Valdez, claiming the sobriety of the Valdez's captain was not an issue in the accident. According to Palast the main cause of the Exxon Valdez accident in 1989 was not human error, but an Exxon decision not to use the ship's radar in order to save money. The Raytheon Raycas radar system would not have detected Bligh Reef itself - as radar, unlike sonar, is incapable of detecting objects under the waterline of a ship. However the radar system would have detected the "radar reflector", placed on the next rock inland from Bligh Reef for the purpose of keeping boats on course via radar.

Palast argues the original owners of the land, the local Alaska Natives tribe, took only one dollar in payment for the land other than a promise not to pollute it and spoil their fishing ground.

In 1998, working as an undercover reporter for The Observer, Palast, posing as a US businessman with ties to Enron, caught on tape two Labour party insiders, Derek Draper and Jonathan Mendelsohn, boasting about how they could sell access to government ministers, obtain advance copies of sensitive reports, and create tax breaks for their clients.[16]

Starting in 2007 Palast published a series of investigations on what aid groups and investors call "vulture funds". Vulture funds are a private equity or hedge funds where companies or people buy the debt of poor countries and sue in courts to recover the funds, often at the expense of aid and debt relief. Prime Minister Gordon Brown commented on the practices saying "We particularly condemn the perversity where Vulture Funds purchase debt at a reduced price and make a profit from suing the debtor country to recover the full amount owed - a morally outrageous outcome".[19]

In 2014 Palast detailed the workings of vulture funds during the crisis of the American automotive industry:

Singer, through a brilliantly complex financial manoeuvre, took control of Delphi Automotive, the sole supplier of most of the auto parts needed by General Motors and Chrysler. Both auto firms were already in bankruptcy.

Singer and co-investors demanded the US Treasury pay them billions, including $350m (£200m) in cash immediately, or – as the Singer consortium threatened – "we'll shut you down". They would cut off GM's parts. Literally.

GM and Chrysler, with no more than a couple of days' worth of parts to hand, would have shut down, permanently forced into liquidation.

Obama's negotiator, Treasury deputy Steven Rattner, called the vulture funds' demand "extortion" ... Ultimately, the US Treasury quietly paid the Singer consortium a cool $12.9bn in cash and subsidies from the US Treasury's auto bailout fund.

Since 2000, Greg Palast has made more than a dozen films for the BBC programme Newsnight with the Investigations Producer Meirion Jones, which have been broadcast in the UK and worldwide. In addition to the films on US elections they have investigated oil companies, the Iraq War, the coup against Hugo Chávez, and the vulture funds which target the poorest countries.

In An Open Letter to Greg Palast on Peak Oil[21]Richard Heinberg offers friendly criticism of Palast who conflates the "amount of oil left" with "peak (maximal) flow rates" for oil, the latter being key to Peak Oil.

After Palast wrote an article critical of left-wing MP George Galloway, Galloway responded by claiming Palast "conflates meetings, truths and half-truths, statements taken out of context to produce a toxic smear which would be actionable in the country he claims to work in." [22]

^San Francisco Chronicle, Friday, December 7, 2007 'Palast says his desire to expose class-warfare stories is rooted in his upbringing in the "ass-end of Los Angeles," a neighborhood wedged between a power plant and a dump. Kids in the neighborhood had two choices, he said: go to Vietnam or work in the auto plant. "We were the losers," he said. He was saved from the war by a favorable draft number. "A lot of people didn't make it out. Because I made it out, and my sister (Geri, a former Clinton administration assistant secretary of labor) made it out, I feel I have this obligation to tell these stories on behalf of all of those people who didn't make it out." [1]